1. Field of the Invention
This invention relates generally to image signal processing and to systems for displaying images. More particularly, this invention relates to scaling image signals from a first resolution to a second resolution.
2. Description of the Background Art
Various resolutions are utilized to display digital images. For computer monitors, common display resolutions currently include VGA (video graphics array), XGA (extended graphics array), SVGA (super video graphics array), and other display standards. VGA displays typically have a resolution of 640.times.480 (horizontal x vertical) pixels. SVGA displays typically have a resolution of 800.times.600 pixels. XGA displays typically have a resolution of 1024.times.768 pixels. SXGA displays typically have a resolution of 1280.times.1024 pixels.
It often occurs in computer-related applications that a digital image must be scaled from one resolution to another resolution. Scaling an image from one resolution to another resolution may be thought of as changing the sampling rate of the image. Scaling of an image signal would be necessary, for example, when a change is made in the resolution at which a display monitor is being operated. For instance, a computer user may change (by way of a function in the Windows operating system) the display resolution from VGA to XGA (or vice-versa) in the middle of a session. Another example where such scaling would be necessary is when an image having a certain resolution is to be printed on a printer having a different resolution.